The hypothalamus produces thyrotropin-releasing hormone (TRH), which stimulates the pituitary gland to release thyroid-stimulating hormone (TSH). A low level of T3 tells the hypothalamus to release ...

Levothyroxine (L-T4 ... TSH isoforms. Central hypothyroidism is characterized by an inappropriately normal or slightly elevated serum TSH level and a blunted (<2-fold rise/ ≤4.0 mIU/L increment ...

If you have hypothyroidism with normal TSH levels, you may still experience symptoms even though your thyroid stimulating hormone (TSH) blood test levels are well within range. Most people whose ...

To exclude the association of a pituitary adenoma that secretes prolactin with a syndrome of 'resistance to thyroid hormone' (RTH), a TSH-releasing hormone (TRH) test was performed. Following the ...

Levels of thyroid hormones in serum are tightly regulated by the hypothalamic-pituitary-thyroid axis (Figure 1). Hypothalamic TSH-releasing hormone (TRH) is secreted mainly from the ...